Aalenian to Lower Bajocian ammonites from the Qiangtang block (North Tibet)

Aalenian and Bajocian ammonites from the Qiangtang block (North Tibet) are described. Comparisons with successions of similar age in Europe allow the establishment of a correlation at zonal level. The relationship between early stephanoceratids and the otoitid Emileites is discussed. Emileites callomoni sp. nov. is erected. Haplopleuroceras, Fontannesia, Witchellia and Sonninia also occur and their significance highlighted. A lectotype for Haplopleuroceras mundum Buckman is designated.